What is l18n?

As you may have noticed, l18n is a contraction of i18n and l10n,
namely 'internationalisation' and 'localization'. It basically provides
lazy translations for names used for localization purposes (e.g. places and
timezones).

I started writing l18n when I was looking for translations for the pytz
library. Indeed, on a multi-lingual site where users can select the timezone
they are in, it's much better if they can select in their language, as in some
cases, the differences with the english name can be significant, hence the
place to look for it when it's sorted in alphabetical order.

And as I am lazy, I thought of a way to - almost - automatically fetch the
translations from the CLDR (Unicode's Common Locale Data Repository) database.

Integrating function to link timezone to country codes, there was no reason not
to try and provide translations also for the latter. In the near future, I -
or contributors - may also add currencies or measurement units fetched from
the CLDR database ...

How does it work?

To use l18n, you first need to install it. It works well with pip:

pip install l18n

Then, in your code:

>>> import l18n

l18n exposes several read-only dictionary-like objects:

l18n.tz_cities

is a mapping between all the timezones listed in pytz.all_timezones
and human-friendly lazy versions of the translated name of the city
in the current language (see Selecting the language below). For example,
if the language is English:

is a mapping between the territory codes as defined in the CLDR and their
localized names, lazily defined. For example:

>>> str(l18n.territories['CZ'])
'Czech Republic' # or 'République Tchèque' in French

Note

The values are translated each time they are evaluated, there is no caching.
This means that the same L18NLazyString / L18NLazyStringsList instance can
be used and produce 2 different outputs if you change the language between
the evaluations.

Note

The values in the above mentionned dictionaries can be overriden by your
own translations. The dictionaries are not read-only and values can be
added or removed at your convenience.

Lazy mappings special features (v.2016.6.3 onwards)

The fore-mentioned tz_cities, tz_fullnames and territories are not
simple dictionaries and provide additional features.

Sorting

When iterating over an L18NMap, the items, keys or values are yielded in
alphabetical order in the currently selected language. For performance, the
results are cached by language, so the sort is only performed once per language.
Note that the values are still lazy objects that are evaluated only when
rendered into a string.

Subsets

It is possible to generate a new L18NMap from an existing one by using the
subset method and passing an iterable of keys that need to be kept in
the new mapping. Any cached sort is also used to generate the new cache, so
that there is nothing to re-calculate in the new subset.

For example, one can generate a map of translations for
pytz.common_timezones:

And in case you want to disable translation and use raw default strings:

>>> l18n.set_language(None)

Utilities

l18n also exposes a few functions that may be helpful in some cases:

l18n.utils.get_country_tzs(country_code)

returns a list of locations for the given country code, sorted in
alphabetical order in the currently selected language

l18n.utils.get_country_code_from_tz(timezone)

returns the country code from a given (untranslated) timezone

Versionning

l18n's main version number matches pytz's version number. l18n
2014.10.X will be fully compatible with pytz 2014.10 whatever the value of
X. Indeed, the primary aim is to keep l18n's translation files consistent
with pytz's timezone names.

Before l18n 2016.6, the pytz version was pinned against the l18n
version. Now, l18n YEAR.MONTH can now be used with any subsequent pytz
version. However, note that there may be missing translations if the 2 versions
are too different from each other. In that case, open an issue to request a
new version of l18n to be published.